Sensory characteristics of antioxidant extracts from Uruguayan native plants: influence of deodorization by steam distillation

Strawberry jams enriched with Acca sellowiana extract

Polyphenols are a popular functional ingredient used in foods due to their antioxidant activity. The leaves of Acca sellowiana, a South American native plant, have a much higher polyphenol content than other popular native plants in the region. In this context, five strawberry jams were developed with increasing amounts of A. sellowiana extract. A panel of trained sensory assessors initially evaluated the sensory profiles of the obtained products. Subsequently, three jams were selected and were evaluated by 96 consumers in two instances. Coded samples were presented in the first session; in the second session, the consumers were presented with information on whether the jams contained antioxidants or not. In both sessions, the acceptability was determined and a description was obtained by means of a check-all-that-apply question. The original jam without A. sellowiana extract presented a polyphenol content of 310.0 mg gallic acid equivalents/100 g and an acceptability higher than 6 in both sessions. A jam was obtained in which the polyphenol content increased to 467.5 mg gallic acid equivalents/100 g, with a sensory profile and acceptability that were similar to those of the original product. Information on enrichment with antioxidants did not affect the acceptability, but it did modify the consumer’s perception, as the consumer showed a predisposition to perceive negative sensory attributes when the product was presented with such information but also perceived it as novel and a good complement to the diet.

Baccharis trimera inhibits reactive oxygen species production through PKC and down-regulation p47 phox phosphorylation of NADPH oxidase in SK Hep-1 cells

Baccharis trimera, popularly known as "carqueja", is a native South-American plant possessing a high concentration of polyphenolic compounds and therefore high antioxidant potential. Despite the antioxidant potential described for B. trimera, there are no reports concerning the signaling pathways involved in this process. So, the aim of the present study was to assess the influence of B. trimera on the modulation of PKC signaling pathway and to characterize the effect of the nicotinamide adenine dinucleotide phosphate oxidase enzyme (NOX) on the generation of reactive oxygen species in SK Hep-1 cells. SK-Hep 1 cells were treated with B. trimera, quercetin, or rutin and then stimulated or not with PMA/ionomycin and labeled with carboxy H₂DCFDA for detection of reactive oxygen species by flow cytometer. The PKC expression by Western blot and enzyme activity was performed to evaluate the influence of B. trimera and quercetin on PKC signaling pathway. p47 ^phox and p47 ^phox phosphorylated expression was performed by Western blot to evaluate the influence of B. trimera on p47 ^phox phosphorylation. The results showed that cells stimulated with PMA/ionomycin (activators of PKC) showed significantly increased reactive oxygen species production, and this production returned to baseline levels after treatment with DPI (NOX inhibitor). Both B. trimera and quercetin modulated reactive oxygen species production through the inhibition of PKC protein expression and enzymatic activity, also with inhibition of p47 ^phox phosphorylation. Taken together, these results suggest that B. trimera has a potential mechanism for inhibiting reactive oxygen species production through the PKC signaling pathway and inhibition subunit p47 ^phox phosphorylation of nicotinamide adenine dinucleotide phosphate oxidase.

Acceptability of Aloysia citriodora-supplemented peach jams

An unsupplemented peach jam and four peach jam samples prepared by supplementing the former with increasing amounts of Aloysia citriodora aqueous extract were subjected to sensory testing. A trained panel of eight assessors initially identified (reaching consensus) the relevant sensory attributes and then rated the jam samples on an individual basis. The jam samples were later evaluated for overall liking and willingness to purchase by a group of 95 interested consumers, who also provided their individual appraisal of the sensory features of the various samples by responding to an open-ended question. Overall, consumers appeared not to accept the sensory modifications introduced in traditional peach jam by the addition of A. citriodora extract, even though they were expressly acquainted with its health benefits. The degree of acceptance of the extract supplement decreased significantly with increasing amounts of extract in the jam. The groups identified to have the least and the greatest tolerance to the sensory modifications introduced in the supplemented jams differed in gender distribution, with male consumers having a greater tolerance than females.